1. Field of the Invention
The present invention relates to a method for the production of laminated glass panes with embedded electrically conductive structures using an interlayer film based on polyvinylacetal having thereon electrically conductive structures.
2. Description of the Related Art
For the production of laminated glass panes with electrically conductive structures, such as heater wires or antennae, methods are customary in which metal filaments are either initially melted on the surface of a normal PVB film or sewn into it, or the electrically conductive structures are applied by screen printing and successive firing on one of the inwards oriented glass surfaces on the laminate. In both cases there is the risk of economic losses, if errors occur during the application on the normal PVB film or when applied onto a prepared glass pane. In the first case, the PVB film, in the second case, the glass, can no longer be used for lamination. Direct printing of PET films with electrically conductive structures, however, is partially established and for example almost invisible heating elements, sensor arrays, etc. can be formed thereon. A leading company in this field is, for example, PolyIC of Fürth, Germany. The disadvantage of a required integration of these structures with electrically conductive printed PET films in laminated glass composites, however, is that always at least 3 layers of film (1×functionalized PET, 2×PVB film) must be used, since PET cannot be melted directly with the functionalized side or the backside on a glass surface.
Another disadvantage is the increased complexity of film packaging, which causes a complication of the film preparation by the processor when combining the feature of “electrically conductive structures” with other functional features such as “acoustic damping”, “band filter”, “wedge-shaped thickness profile”, “color hue”.
The production of laminated glass composites with conductive layers, which are incorporated into the entire surface of the laminate is, for example, known from EP 2409833. WO 2010/030413 discloses electrically conductive interlayer films which are mounted between two electrodes. This results in a high consumption of material in the conductive layers in addition to a reduced transparency of the laminate.